on pagefaults and nonsense :) + a sound-related problem

Teunis Peters (teunis@usa.net)
Wed, 30 Jul 1997 19:47:33 -0600 (MDT)


Is there a way to do userspace pagefault handling?

This was talked about last year but I never heard anymore about it...

Some possible uses:
1. emulating linear graphics buffer (most older VGA cards only support up
to 64K of memory visible at a time - emulating linear memory would make
writing drivers for these easier)

[alternatives : Don't bother; go ahead and write the <gleah> 16bit code]

2. A JIT (just-in-time) compiler that produces new executable code
on-the-fly based on requested pages;
: basically so compiling can be done on-demand rather than all at once

[alternative : lockable stream output from compiler;
(how to wait on lock in executing stream though?)]

.. there's prolly other advantages but I can't think of any at the
moment... <g>...

As I'm writing a JIT (it's the same program I've mentioned before as a GUI
+ a couple of other things... <G>) this could be of some use...

Oh, and on sound : Any idea how to use /dev/dsp (or the like)
bidirectionally? The docs aren't all that clear [as a matter of fact,
they seem to be nonexistant].

I have a bidirectional soundcard (GUS) and all I want is to be able to
read from (say) line-in; amplify; then write back out to soundcard. My
CDROM (on line-in) is too quiet and GUS doesn't have a built-in amplifier
for anything other than wave-audio channels.)

It'd also be nice to do i-phone type stuff :)

TIA and G'day, eh?
- Teunis

Oh, and one last question: Would it be a good idea to use asm/spinlock.h
as a model for doing thread locks? This is for assembly code (or lisp).

[need read-many/write-once and read/write locks - just like 'spinlock.h'
has]

I only have one processor and wish to make my code SMP-friendly (or at
least SMP-safe).. the code is very multithreaded.